This invention relates generally to apparatus for measuring the speed of an object and particularly to low cost speed measuring apparatus suitable for applications such as toys or amusement devices.
Within the toy or amusement device industry, a need often arises to provide measurement of a moving object. A typical environment in which a requirement for measuring object speed arises is found in toy vehicle play sets. Historically, apparatus such as plural spaced apart switches or inferred or ultrasonic detectors have been utilized for this purpose. The basic apparatus operates by measuring the time interval between the moving toy vehicles encounter with the first and second sensors or switches.
While such apparatus has enjoyed commercial success in a number of applications, there remains nonetheless a continuing need in the art for evermore improved cost effective and sophisticated speed measuring apparatus suitable for use in toys or amusement devices.
Accordingly, it is a general object of the present invention to provide an improved speed measurement apparatus. It is a more particular object of the present invention to provide an improved speed measurement apparatus which is suitable in cost and complexity for use in a toy or amusement device environment.
In accordance with the present invention there is provided for use in measuring the speed of a moving object, speed measurement apparatus comprising: an ultrasonic transmitter having a transmitting transducer and output signal source for producing ultrasonic energy; an ultrasonic receiver having a receiving transducer for receiving ultrasonic energy reflected from an object to produce a reflected signal; a mixer producing a beat frequency signal between the reflected signal and the output signal; a controller for determining the frequency of the beat frequency signal; and display means for displaying a speed value derived from the frequency of the beat frequency signal.